We propose adding a longitudinal component to our current NIMH-funded study of juvenile detainees (MH54197) to complement the NIMH-funded study, "Use, Need, Outcomes and Costs in Children and Adolescent Population" (UNOCCAP), of general population youth. Although researchers speculate that many juvenile detainees have alcohol, drug or mental (ADM) disorders, there are few empirical data. Our current study is the first large-scale study of alcohol, drug and mental health (ADM) service needs of juvenile detainees (n=1800 detainees; 1200 males and 600 females, 10-17 years old). Our current study does not include follow-up interviews and no general population comparisons. Because we collect extensive baseline data and (funded by grants from NIMH, NIDA the MacArthur Foundation), we are tracking them, we have a unique opportunity. By adding a longitudinal component, we could investigate the incidence and course of ADM disorders during a key developmental period as well as whether or not their disorders are detected, the time of services they receive, and their level of unmet meed. Adding a longitudinal component to our current study would also allow us to study prospectively three risky behaviors- drug use, violence and HIV risk behaviors- all of which are major public health problems and are prevalent among delinquent youth. The proposed study has three specific aims: (1) ADM Service Needs. We will re-assess the extent and distribution of ADM disorders (including incidence, duration, patterns, sequence of co-morbidity and risk and protective factors) and functional impairments among our subjects and compare them to general population (UNOCCAP) rates. (2) Service Utilization. We will assess whether or not juveniles who need services (as determined in Specific Aim #1) receive them after their cases reach disposition (whether they are in the community or incarcerated), from which system (e.g., mental health, juvenile or adult justice, child welfare, etc.), which services they receive, and how patterns of use differ from those of general population youth. (2) Risky Behaviors. We will assess the patterns and developmental sequence of drug use, violence, and HIV risk behaviors in our sample, including the antecedents of these risky behaviors (especially ADM disorders), how youth developed these risky behaviors and how these behaviors are interrelated. This proposal responds to the NIMH National Plan for Research on Child and Adolescent Mental Disorders, which called for research on mental health services among juvenile offenders; to Healthy People 2000, which called for research on reducing HIV risk behaviors; to NIDA's Program Announcements PA-95-022, PA-95-057, PA-95-059, PA-955-055, and PA-95-083; and to NIDA's March, 1996 amendment requesting research on the co- occurrence, developmental sequence, and health consequences of violence, drug abuse and HIV/AIDS.